qian = float(input("价格是："))  # input
if qian > 100:
    qian -= 50  # qian= qian-50
elif qian > 50:
    qian -= 20
elif qian >= 30:
    qian -= 10
if input("请输入是否是会员 yes/no") == "yes":
    qian *= 0.8
    # print("所需付款：",qian)
print("所需付款：", qian)
